The electrochemical methods-based protocol for simultaneous detection of tetracycline (TC) from antibiotics class and fluoxetine (FXT) from anti-depressive pharmaceuticals class, which belongs to emerging pollutants from water, was developed in this study using carbon nanofiber-epoxy composite electrode (CNF). The electrochemical behaviour of each pharmaceutical on CNF was considered the basis for simultaneous detection of both pharmaceuticals from water. TC electrooxidation on CNF occurred in two steps and, consequently, two detection potentials are considered. FXT electrooxidation occurred in one step that is overlaid to the first step of TC detection, this step being considered as cumulative for both pharmaceuticals. Each electrochemical method of cyclic voltammetry (CV) and differential-pulsed voltammetry (DPV) allowed detecting cumulative presence of TC and FXT at the detection potential ranged between 0.65 and 0.815 V vs. SCE and the selective detection of TC at the detection potential ranged between 0.956 and 1.14 V vs. SCE. The electroanalytical parameters related to the lowest limit of detection and sensitivity recommended this electrode to exhibit the potential for practical applications in the electrochemical detection of certain pharmaceuticals as emerging pollutants from water.

Pharmaceuticals contaminants in waters exhibit a significant threat on the human health and the ecosystem quality. This research demonstrates the utility of a silver-doped zeolite-modified carbon nanofiber-epoxy (AgZ-CNF) prepared by two-roll mill method in development of the fast methodology for the detection of fluoxetine (FXT) in the aqueous solution. The results showed the role of zeolite that improved the sensitivity and the limit of detection of FXT resulted to the possibility to propose a specific preconcentration-based detection protocol. The silver contributed to decreasing the anodic over potential for FXT oxidation and hence, for FXT detection. The best sensitivity of 2.007 μA μM-1 and lowest limit of detection of 19 nM are were obtained for preconcentration-cyclic voltammetry based scheme, which is very promising for the detection of FXT at trace levels. Also, the chronoamperometry operated at 0.350 V/SCE specific to silver involving and +1.1V/SCE characteristics to the carbon nanofiber, allowed FXT detection in the aqueous solution. The long life time and the stable response for FXT detection was found for AgZ-CNF composite electrode, which suggests its practical utility in FXT determination in the real water sources.